Electric incandescent lamp.



E. TERRY. ELECTRIC INCANDESCENT LAMP.

APPLICATION mm ocr. 2, I915.

1,262,141 Patented Apr. 9, 19m

L 0 R k 11 I FIG 2 ban/am? jrr Invent EDWARD TERRY, OF BRIXTON, LONDON, ENGLAND.

.ELECTRIC INCANDESCENT LAMP.

Specification of Letters Patent.

Patented Apr. 9, 1918.

Application filed October 2, 1915. Serial No. 53,742.

To all whom it may concern:

Be it known that I, EDWARD TERRY, a subject of the King of Great Britain, residing at Milton Hall, 117 Loughborough Park, Brixton, London, S. W., England, have invented a new and useful Improvement in Electric Incandescent Lamps, of which the following is a specification.

This invention has reference to electric incandescent lamps of the kind in which the filament supporting pedestal forms part of a detachable stopper or plug adapted for gas tight engagement with the lamp bulb so that when the filament becomes broken or its efliciency impaired the stopper may be separated from the bulb the filament renewed and the parts reassembled.

Numerous attempts have heretofore been made to construct a practicable and serviceable lamp of this kind but all such attempts have failed to produce a commercially successful article chiefly for the reason that where the means for securing a gas tight joint between the lamp bulb and'the stopper have been effective great difficulty has been experienced in separating the parts when it is desired to renew the filament the operation being attended with fracture either of the bulb or the stopper or both.

. Under the present invention however I have succeeded in producing an incandescent lamp which when exhausted will hold the high vacuum requisite in a lamp of this kind for an indefinite period and in which the parts may be readily separated when repairs are necessary without the'danger of breakingi or fracture of any part of the lamp.

hese ends and such others as may be incidental thereto or as may hereinafter appear are attained by the means which I will now proceed to describe in detail and for a correct understanding thereof reference should be had to the accompanying drawings in which:

Figure 1 illustrates in vertical section the upper portion of an incandescent electric lamp embodying my invention and Fig. 2 represents partly in section and partly in elevation a slightly modified construction.

Referring now to Fig. 1 it will be seen that I provide the bulb a with 2. preferably slightly tapered neck 6 of sufficient diameter to admit of the filament carried by the stopper being passed therethrough as will hereinafter be described. The neck 6 is formed with a recess 0 on its inner annular Wall and is also provided with a circumferential flange d. The glass stopper e is shaped to fit the neck or mouth 6 of the bulb a and is formed with a recess f which 00- operates with the recess 0 of the neck 6 to form a well it for the reception of the sealing medium as hereinafter explained said stopper also having a circumferential flange 9 which when the stopper is in position is spaced apart from the flange (1 on the neck 6 of thebulb to form a cavity in communication with the well it.

Formed integrally with the stopper 6 is a depending tubular member 2' to which is fused the filament supporting pedestal j said tubular member serving for the reception of the leading in wires is the lower ends of which are attached to the usual platinum connections Z and sealed to form a gas tight joint as is usual in the manufacture of incandescent lamps. Held within the tubular member i such as by means of a suitable cement m are two metallic tubes 92 the lower ends of which are adapted to receive and make electrical connection with the leading in wires k. The opposite ends of the aforesaid tubes at are preferably slightly flared to receive and make electrical connection with the leading in wires 0 carried by the cap p-to be presently describedadapted for engagement with the standard lamp socket or fitting. An aperture 9 is provided in the wall of the tubular member 2' to which is fused a tube 1 adapted for attachment to a suitable vacuum pump whereby when the parts are assembled as hereinafter explained the bulb a may be exhausted.

I will now describe the assemblage of a lamp embodying my invention. The filament 8 having been mounted on the spider t the stopper'e is inserted in the neck 6 of the lamp bulb and a strip of oiled silk u or other material wrapped around the edges of the flanges d, g. A quantity of mercury which I have found by exhaustive experiments to be the most suitable sealing material-is now introduced into the cavity between the flanges d, g and into the well I and the bulb is then exhausted through the tube 1' the end of which is sealed when the requisite degree of vacuum is obtained. The metallic cap p carrying the leading in wires 0 is now arranged in position care being taken that said wires are inserted in electrical contact in the tubes n said-cap being secured against rotation in any suitable manner.

When it is necessary for any reason to repair or renew the filament the cap 1) is first or precautionary measure for holding the vacuum within the bulb and to this end I provide the stopper 6 with an angularly disposed circumferential groove or channel to which is filled with mercury through an aperture 00 in the neck of the bulb the stopper beingthen partially rotated to' interrupt communication between -said aperture and groove or channel w. Otherwise the'construction is similar to that described with reference to Fig. 1.

What I claim is:

1. An incandescent electric lamp comprising in combination a lamp bulb having a neck with an outwardly projecting circumferential flange, a circumferential roove on the inner annular wall of the nec: of said bulb, a detachable stopper having an outwardly projecting circumferential flange normally spaced apart from the flange on the bulb and a circumferential groove on the outer annular wall of said stopper registering with the circumferential groove in the bulb neck to form an annular well in communication with the cavity formed by the spacing apart of the bulb and stopper flanges, a sealing medium in said cavity and well, means carried by said stopper for supporting the leading in wires and filament, and means for exhausting the lamp bulb.

2. An incandescent electric lamp comprising in combination a lamp bulb having a neck with an outwardly projecting circumferential flange, a circumferential groove on the inner annular wall of the neck of said bulb, a detachable stopper having an out-- wardly projecting circumferential flange normally spaced apart from the flange on the bulb and a circumferential groove on the cap carrying leading in wires an outer annular wall of said stopper register- ,ing with the groove in the bulb neck to form an annular well in communication with the cavity formed by the spacing apart of the bulb and stopper flanges, a sealing medium in said cavity and well, a depending tubular member carried by said stopper, means located in said tubular member for making electrical connection with the leading 'in wires of the lamp, a,fila1nent support secured to said tubular member, a filament, and means for exhausting the lamp bulb.

3. An incandescent electric lamp comprising in combination a lamp bulb having a neck with an outwardly projecting circumferential flange, a circumferential groove extending over the inner annular wall of the neck of the said bulb and the face of the tering with the groove in the bulb neck to' form a well in communication with the cavity formed by the spacing apart of the bulb and stopper flanges, a sealing medium consisting of mercury in said cavity and well, a depending tubular member carried by said stopper, tubes located in said tubular member for. making electrical connection with the leading in wires of the lamp, a filament support secured to said tubulanmember, a filament, an aperture in said tubular member, and an exhausting tube in communication with said aperture.

t. An incandescent electric lamp comprising in combination a lamp bulb having a neck with an outwardly projecting circumferential flange, a circumferential groove extending over the inner-annular wall of the neck of the said bulb and the face of the flange thereof, a detachable stopper havin an outwardly projecting circumferentia flange and a circumferential groove extending over the outer annular wall of said stopper and the face of the flange thereof and registering with the groove in the bulb neck to form a well, a sealing medium in said well, means carried by said stopper for'supporting the leading in wires and filament means for exhausting the lamp, a cap to inclose the stopper and said circumferential flan es, said being adapted for engagement with the lamp socket or fitting.

5. An incandescent electric lamp comprising in combination a lamp bulb having a neck with an outwardly projecting circumential groove on the outer annular Wall of means for exhausting the lamp, 3. cap to insaid stopper registering with the groove in close the stopper and said circumferential the bulb neck to form a Well, an obliquely flanges, said cap carrying leading in wires 1 disposed circumferential groove in said stopand being adapted for engagement with the 5 per, a sealing medium in said Well and lamp socket or fitting.

groove, means carried by said stopper for supporting the leading in Wires and filament, EDWARD TERRY. 

